WO2018095362A1

WO2018095362A1 - Phosphaphenanthrene-structure reactive fire retardant and application thereof

Info

Publication number: WO2018095362A1
Application number: PCT/CN2017/112584
Authority: WO
Inventors: 戴李宗; 柳超; 陈国荣; 黄佳美; 许一婷; 曾碧榕; 罗伟昂; 袁丛辉; 何凯斌; 刘新瑜
Original assignee: 厦门大学
Priority date: 2016-11-23
Filing date: 2017-11-23
Publication date: 2018-05-31
Also published as: US10618923B2; CN106554483A; US20190382427A1; CN106554483B

Abstract

Disclosed are a phosphaphenanthrene-structure reactive fire retardant and an application thereof. The preparation method comprises: enabling 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), p-hydroxy benzaldehyde (4-HBA), and 5-aminomethyl-1,3-diphenyl-1,3,5-diphosphonitryl heterocycles to react under a certain condition to obtain the reactive fire retardant of a benzene ring rigid structure containing polyhydroxy. Compared with an ordinary fire retardant, the phosphaphenanthrene-structure reactive fire retardant has the characteristics that polyfunctionality is achieved, the molecular structure is stable, the hydrolysis resistance is good, and migration in epoxy resin is not prone to occurring; moreover, the fire retardant property of the epoxy resin can be remarkably improved.

Description

Phosphorus phenanthrene structure reactive flame retardant and application thereof

Technical field

The invention relates to a flame retardant, in particular to a phosphorus phenanthrene structure reactive flame retardant and application thereof.

Background technique

Since the invention of epoxy resin by both Castan and Greenlee in 1936, epoxy resin has been used in transportation, infrastructure construction, ship and marine, aerospace and electrical engineering for almost all aspects of social life due to its good physical and chemical properties. Has a wide range of applications. Despite this, due to the flammability of general-purpose epoxy resins, they are not suitable for use in many fields. With the development of the epoxy resin industry in the direction of refinement, the development of new and efficient flame retardants to improve the flame retardant ability of epoxy resin has become a research hotspot.

At present, epoxy resin flame retardants are various in variety and classification methods are also different. According to the elemental content of the flame retardant, it can be classified into a phosphorus-based, nitrogen-based, silicon-based, fluorine-based flame retardant or a synergistic flame retardant containing two or more elements. According to whether the flame retardant has a functional group capable of reacting with the epoxy resin, it can be further classified into an additive type and a reactive type flame retardant. The reactive flame retardant has a long-lasting flame retardant effect, does not migrate in the epoxy resin, and can maintain or improve its mechanical properties while improving the flame retardancy of the epoxy resin.

Gao et al. (Gao LP, Wang DY, Wang YZ, et al. Polymer Degradation and Stability, 2008, 93(7): 1308-1315.) synthesized a single-reactive functional group of phosphorus-containing monomer DODPP, and then different proportions The DODPP reacts with DGEBA to obtain different phosphorus content epoxy resins. When the phosphorus addition amount is 2.5%, the obtained cured product can be tested to a V-0 level by UL-94, and the LOI value is 30.2%. The heat release test resulted in a decrease in the values of HRR, PHRR, and Av-HRR. Murias (Murias P, Maciejewski H, Galina H. European Polymer Journal, 2012, 48(4): 769-773.) synthesized two kinds of siloxanes having an amino group or an epoxy group, respectively, and Ethyltetramine is a curing agent and co-cured with a low molecular weight epoxy (E6) to obtain an epoxy cured product. When the amount of siloxane added is increased, the LOI value of the obtained epoxy cured product is also increased from 21.9%. Up to 23.9%, and the impact strength will be significantly improved.

Summary of the invention

The invention relates to a phosphorus phenanthrene structure reactive flame retardant and application thereof.

The phenanthroline structure reactive flame retardant comprises tetramethylol phosphine sulfate (THPS), aniline, glacial acetic acid, p-hydroxybenzaldehyde (4-HBA) and 9,10-dihydro-9-oxa-10 - a phosphorus phenanthrene-10-oxide (DOPO) reaction.

The structural formula of the phenanthroline structure reactive flame retardant is as follows:

The synthetic route of the phosphorus phenanthrene structure reactive flame retardant is as follows:

The synthetic steps of the phosphorus phenanthrene structure reactive flame retardant are as follows:

(1) Method for synthesizing 5-aminomethyl-1,3-diphenyl-1,3,5-diazaphosphorane (hereinafter referred to as substance I) by Frank A Drake Jr G L. The Journal of Organic Chemistry, 1972, 37(17): 2752-2755;

(2) Add DOPO, 4-HBA and substance I to a three-necked bottle, add a catalytic amount of p-toluenesulfonic acid, protect with nitrogen, heat up and magnetically stir, and react for a certain period of time;

(3) After completion of the reaction, separation was carried out by column chromatography using silica gel as a stationary phase.

Wherein the molar ratio of the substance I, 4-hydroxybenzaldehyde, DOPO is 1:2-6:3-7;

The catalyst p-toluenesulfonic acid is used in an amount of from 1% to 10% by mass of the substance I;

The solvent is toluene; the reaction temperature is from 100 ° C to 180 ° C; and the reaction time is from 8 to 20 h.

The preparation method of the polyfunctional reactive flame retardant is characterized by comprising the following steps:

1. The molar ratio of DOPO, 4-HBA and substance I in step (2) can be 4:3:1-6:5:1, and the amount of catalyst p-toluenesulfonic acid is 2%-8 of the mass fraction of substance I. %. The reaction temperature is from 120 ° C to 160 ° C, and the reaction time is from 10 to 16 hours.

2. In the step (3), the column developer was separated into ethyl acetate: petroleum ether = 4:1 (volume ratio), and 5 mL of glacial acetic acid was added per 100 mL of the developing agent.

The flame retardant of the present invention has the following advantages:

(1) The flame retardant contains three hydroxyl groups in the molecular structure, which can react with the epoxy group and participate in the curing of the epoxy resin. Compared with the common reactive flame retardant, its functionality is higher, and the modified epoxy resin is more firmly bonded to the matrix.

(2) The flame retardant has a plurality of benzene rings and a fused ring structure in the molecular structure, and the phosphorus, carbon and nitrogen atoms form a six-membered heterocyclic ring, and therefore, it has higher thermal stability and hydrolysis resistance.

(3) The relative molecular mass of the flame retardant is 1321, which is better than that of the small molecule flame retardant in the epoxy resin without migration.

DRAWINGS

1 is a nuclear magnetic resonance spectrum of the flame retardant of Example 1.

2 is a nuclear magnetic phosphorus spectrum of the flame retardant of Example 1.

detailed description

The invention is further illustrated by the following examples.

Example 1

2.16 g (0.01 mol), 0.732 g (0.006 mol), 0.722 g (0.002 mol) of DOPO, 4-HBA and substance I were added to the three-necked flask, and then 0.0864 g (the relative substance I mass fraction was 4%). The p-toluenesulfonic acid was protected by nitrogen, heated to 130 ° C, and stirred under magnetic stirring for 12 h. After completion of the reaction, silica gel was used as a stationary phase, ethyl acetate: petroleum ether = 4:1 as a developing solvent, and 5 mL of glacial acetic acid was added per 100 mL of the developing solvent, and the product was isolated by column chromatography.

The nuclear magnetic spectrum is shown in Figures 1 and 2.

Example 2

2.592g (0.012mol), 0.732g (0.006mol), 0.722g (0.002mol) of DOPO, 4-HBA and substance I were added to the three-necked flask, and then 0.0864g (the relative substance I mass fraction was 4%). The p-toluenesulfonic acid was protected by nitrogen, heated to 130 ° C, and magnetically stirred for 16 h.

After completion of the reaction, silica gel was used as a stationary phase, ethyl acetate: petroleum ether = 4:1 as a developing solvent, and 5 mL of glacial acetic acid was added per 100 mL of the developing solvent, and the product was isolated by column chromatography.

Example 3

2.592 g (0.012 mol), 0.976 g (0.008 mol), and 0.722 g (0.002 mol) were added to the three-necked flask. DOPO, 4-HBA and substance I, and then added 0.0864 g (4% by mass of substance I) of p-toluenesulfonic acid, protected by nitrogen, heated to 130 ° C, and magnetically stirred for 16 h. After completion of the reaction, silica gel was used as a stationary phase, ethyl acetate: petroleum ether = 4:1 as a developing solvent, and 5 mL of glacial acetic acid was added per 100 mL of the developing solvent, and the product was isolated by column chromatography.

Example 4

2.592g (0.012mol), 0.732g (0.006mol), 0.722g (0.002mol) of DOPO, 4-HBA and substance I were added to the three-necked flask, and then 0.0864g (the relative substance I mass fraction was 4%). The p-toluenesulfonic acid was protected by nitrogen, heated to 130 ° C, and stirred under magnetic stirring for 12 h. After completion of the reaction, silica gel was used as a stationary phase, ethyl acetate: petroleum ether = 4:1 as a developing solvent, and 5 mL of glacial acetic acid was added per 100 mL of the developing solvent, and the product was isolated by column chromatography.

The preparation steps and flame retardant test steps of the pure epoxy resin and the flame retardant modified epoxy resin are as follows.

(1) Preparation of pure epoxy resin

Weigh 20g epoxy resin E-51, heat to 100 ° C, add 4g curing agent 4,4 '-diaminodiphenylmethane, stir evenly, pour into the mold, heat at 120 ° C for 4 hours, then keep warm at 140 ° C 2 Hours, and finally incubated at 160 ° C for 2 hours.

(2) Preparation of reactive flame retardant modified epoxy resin

Weigh 20g epoxy resin E-51, heat up to 100 ° C, add 2.13g of the flame retardant (the quality of the phosphorus element is 1% of the mass of the epoxy resin, the following flame retardant addition amount is based on the mass of phosphorus element After stirring and dissolving, the small molecular substance is removed under vacuum, 4 g of curing agent 4,4'-diaminodiphenylmethane is added, stirred uniformly, poured into a mold, kept at 120 ° C for 4 hours, and then kept at 140 ° C for 2 hours. And finally at 160 ° C

The reaction type flame retardant-modified epoxy resin was obtained by keeping it for 2 hours. In this way, 6.39 g, 10.66 g of the flame retardant (corresponding to a phosphorus content of 3%, 5%, respectively) was added to 20 g of epoxy resin to prepare a modified epoxy resin.

(3) The obtained sample was tested for its oxygen index according to the method of GB/T 2406.2-2009.

Test results are shown in Table 1.

Table 1 Test results of limiting oxygen index of modified epoxy resin with different phosphorus content

The above is only the preferred embodiment of the present invention, and thus the scope of the present invention is not limited thereto, that is, equivalent changes and modifications made in accordance with the scope of the invention and the contents of the specification should still be covered by the present invention. Within the scope.

Claims

A phosphorus phenanthrene structure reactive flame retardant characterized in that the molecular structure is as follows:
The synthetic route of a phosphaphenanthrene structure reactive flame retardant according to claim 1 is as follows:
A method for preparing a phosphaphenanthrene structure-reactive flame retardant according to claim 1, comprising the steps of:

Under the protection of nitrogen, the reactant 5-aminomethyl-1,3-diphenyl-1,3,5-diazaphosphorane, 4-hydroxybenzaldehyde, DOPO and solvent are sequentially added to the vessel, and then added. P-toluenesulfonic acid as a catalyst, the temperature is raised for a period of time, a pale yellow solution is obtained, and the solvent is removed, and the obtained substance is separated by column chromatography to obtain a phenanthroline structure-reactive flame retardant;

The molar ratio of 5-aminomethyl-1,3-diphenyl-1,3,5-diazaphosphorane, 4-hydroxybenzaldehyde, DOPO is 1:2-6:3-7;

The catalyst p-toluenesulfonic acid is used in an amount of from 1% to 10% by mass of the 5-aminomethyl-1,3-diphenyl-1,3,5-diazaphosphine heterocycle;

The solvent is toluene; the reaction temperature is from 100 ° C to 180 ° C; and the reaction time is from 8 to 20 h.
A method for preparing a phosphorus phenanthrene structure reactive flame retardant according to claim 3, characterized in that the 5-aminomethyl-1,3-diphenyl-1,3,5-diazaphos The molar ratio of the heterocyclic ring, 4-hydroxybenzaldehyde, and DOPO is 1:3-5:4-6.
The method for preparing a phosphaphenanthrene structure-reactive flame retardant according to claim 3, characterized in that the amount of the p-toluenesulfonic acid of the catalyst is 5-aminomethyl-1,3-diphenyl-1,3 ,5-diazaphosphorus 2% to 8% of the ring mass fraction.
The method for preparing a phosphaphenanthrene structure-reactive flame retardant according to claim 3, wherein the solvent is toluene; the reaction temperature is from 120 ° C to 160 ° C; and the reaction time is from 10 to 16 hours.
The method for preparing a phenanthroline structure-reactive flame retardant according to claim 3, wherein the column chromatography uses 300-400 mesh silica gel as a stationary phase, and ethyl acetate: petroleum ether volume ratio = 4:1 For the mobile phase, 5 mL of glacial acetic acid was added per 100 mL of developer.
The use of a phosphorus phenanthrene structure reactive flame retardant according to claim 1 for preparing a flame retardant polymer material.
A method for preparing a flame-retardant polymer material, comprising the steps of: weighing an epoxy resin prepolymer to a certain temperature, stirring, adding a certain mass fraction of the phosphorus-phenanthrene structure reactive flame retardant according to claim 1. Stir until the mixture is in a uniform transparent state, add the curing agent in a stoichiometric ratio until completely dissolved, pour into an aluminum mold, and set a heating program to cure to obtain a flame retardant epoxy resin.
The method for preparing a flame-retardant polymer material according to claim 9, wherein the epoxy resin prepolymer is heated to 85 to 100 ° C, the stirring time is 20 to 40 min; and the phosphorus phenanthrene structure is added. The flame retardant mass fraction is 1-30%, the stirring time is 40-80 min; the temperature programming process is solidified at 120-130 ° C for 4 h, the temperature is kept at 130-150 ° C for 2 h, and finally at 150-170 ° C for 2 h.